Static card reader and control system for access apparatus

ABSTRACT

A coded card is located at one end of a plurality of parallel sensors, each having a coil in series with a respective resistor, the junctions of such coils and resistors being connected to a gate network. A second card is inserted at the opposite ends of the sensors, and a switch actuated thereby effects operation of control circuitry to cause a voltage pulse to be applied across all resistor-coil combinations, simultaneously. Both cards have magnetized spots perpendicular to the card surfaces, and such spots are aligned with respective sensors. only where the fields of each pulsed coil and the spot aligned therewith are in the same relation, e.g., opposing, the gate network effects operation of a solenoid of access apparatus.

United States Patent [1 1 Rogers et al.

1 1 STATIC CARD READER AND CONTROL SYSTEM FOR ACCESS APPARATUS [75] lnventors: Waldo 1. Rogers, Arcadia; Robert J. Fox, Los Angeles; Eric W. Moulton, Santa Monica, all of Calif.

[73] Assignee: Ruseo Industries, lnc'., Pasadena,

Calif.

[22] Filed: Jan. 4, 1973 [21] Appl. No.: 320,905

[52] U.S. Cl. 235/61. D, 179/1002 A, 340/174.l H

[51] Int. Cl. G06k 7/08, G1 lb 5/00 [58] Field of Search 235/6l.1l D, 61.7 B; 340/149 A, 174.1 H; 194/4 R; 179/1002 A [56] References Cited UNITED STATES PATENTS 3,686,479 8/1972 Rogers et a1 235/61.1l D 3,154,761 10/1964 OGorman 340/149 A 51 Dec. 18, 1973 3,312,372 4/1967 Cooper 235/6l.l1 D

Primary ExaminerThomas J. Sloyan Attorney-Perry E. Turner [57] ABSTRACT A coded card is located at one end of a plurality of parallel sensors, each having a coil in series with a respective resistor, the junctions of such coils and resistors being connected to a gate network. A second card is inserted at the opposite ends of the sensors, and a switch actuated thereby effects operation of control circuitry to cause a voltage pulse to be applied across all resistor-coil combinations, simultaneously. Both cards have magnetized spots perpendicular to the card surfaces, and such spots are aligned with respective sensors. only where the fields of each pulsed coil and the spot aligned therewith are in the same relation, e.g., opposing, the gate network effects operation of a solenoid of access apparatus.

fX/f 1 105 I SHEU 1 BF 2 PATENTH] DEC] 8 I873 sum 2 ur 'PAIENTEDUECI 81873 STATIC CARD READER AND CONTROL SYSTEM FOR ACCESS APPARATUS The system additionally includes a time-restricted or zone access control and a code-changing control, each of which has a switch with its movable contact connected to the gate network, and wherein respective resistor-coil junctions are disconnected from the gate network and connected to respective fixed contacts of such switches. For zone access, the gate network effects operation of the solenoid only for an inserted card that has a predetermined one of its spots aligned with the coil to which the movable contact of the associated switch is connected. For code changing, a pair of electromagnets are positioned so that respective portions of the inserted cards are aligned therewith, and the gate network effects energization of the electromagnets to change the magnetization of the two portions, including that associated with the coil to which the movable contact of the associated switch is connected.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to electrically controlled access apparatus operable by magnetically coded cards.

2. Description of the Prior Art In known electrically controlled access apparatus, a magnetized card inserted in a carriage actuates movable magnets to move them out of blocking engagement with the carriage, thus permitting the card to physically move the carriage to close a switch that is in circuit with electromagnetic means for operating a door strike, gate release, or the like. Such arrangements are disclosed in U.S. Pat. No. 2,931,953 and No. 3,154,761. Movable magnets in such apparatus can be rendered inoperable by dirt and other foreign particles which increase the friction to the point where the magnetomotive force of a card spot is insufficient to effect movement of the magnets. To keep such devices in operating condition requires undesired outlays of funds for maintenance, repair and replacement.

SUMMARY OF THE INVENTION This invention embraces, for access apparatus to be operated electrically under control of a magnetic card, a plurality of electromagnetic sensors to be energized from a pulse source, such sensors being parallel to permit a card to be placed at one end and with mangetized spots aligned with respective sensors, gate means to develop a signal of one logic level when the fields of all aligned sensors and spots are in a predetermined relation, control circuitry for the access apparatus, and switch control means operable by the card to condition the control circuitry via the pulse source and gate means for operating the access apparatus. Also embraced are means for selectively restricting operation of the access apparatus by cards which have different predetermined spots to be sensed at different times or locations, and means for changing the polarities of predetermined spots to thereby change the card codes.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary sectional view of a housing with electromagnet sensors and magnetic cards dis posed at their opposite ends;

FIG. 2 is a combined schematic and block diagram of a system of the invention;

2 FIG. 3 is a combined schematic and block diagram of a portion of the system of FIG. 2; and

FIG. 4 is a graph to aid in explaining the operation of the invention.

DESCRIPTION OF PREFERRED EMBODIMENT Referring to FIG. I, a housing 10 has an upper wall 12 with a plurality of openings in which the upper ends of electromagnet sensors 14 are secured. Placed on top of the wall 12, is a magnetic card 16 which is magnetized at a number of spots so that the fields of such spots are aligned with respective sensors. The housing has a lower wall 18 spaced from the lower ends of the sensors 14, the distance bewteen the lower ends of the sensors and the wall 18 being such as to permit a magnetic card 20 to be inserted between them. The card 20 is also magnetized in a number of spots so that the fields of such spots are aligned with respective sensors 14. In one arrangement, as indicated, the spots of the cards 16 and 20 are so arranged that a sensor 14 is aligned with only one spot, i.e., no sensor is aligned with spots in both cards.

When the magnetic card 20 is fully inserted in the housing, its inner end actuates the movable contact of a single pole, double-throw switch 22 to condition a system of the invention for operating access apparatus. In this connection, and referring to FIG. 2, the switch 22 is shown with its movable contact 24 connected to a point of reference or ground potential and its fixed contacts 26, 28 connected to a transient squelch circuit 30, such as a flip-flop, having complement output terminals respectively connected to a pulser 32, which may be a conventional one-shot device, and to the set terminal, S, of a logic circuit 34 which may be comprised of a flip-flop.

As shown, the pulser 32 is operatively connected to the positive terminal of a power supply 36 which in one example is a lowvoltage (e.g., 12.6 volts) AC source 38 connected to a rectifier and charging network 40 for charging a capacitor 42 that is utilized to pulse the coils of the sensors 14. In this latter connection, coils 44 are diagramatically illustrated for the sensors in FIG. 1. Sensors may, for example, be of the type disclosed in U.S. Pat. No. 3,686,479, entitled Static Reader System for Magnetic Cards, assigned to the same assignee as the present application. It will be understood that the coils 44 may be wound so that when they are pulsed, the magnetic fields set up in the different cores may be in different directions. However, for purposes of this invention, such fields when established all have the same relation with respect to the fields of the spots and the cards 16, 20 with which the sensors are aligned,

e.g., opposing.

Further in this connection, and referring to FIG. 2 along with FIG. 1, there is shown a plurality of coils 44 each having a resistor 46 connected in series therewith. The upper ends of the resistors 46 are connected to the positive terminal of the power supply 36, and the lower ends of the coils 44 are connected together to an electronic switch 48 that is controlled by the pulser 32. Additionally, the junction of each serially connected coil and resistor has a respective connection to a gate network 50. The electronic switch 48 is adapted to be pulsed by the pulser 32 to connect the serially connected coils and resistors to ground, thereby permitting the coils 44 to be pulsed and causing voltages, developed across them to be applied to the gate network 50.

The outputs of the gate network 50 and the pulser 32 are connected to respective data and clock input terminals, D and C, of logic circuit 34. The logic circuit 34 has a data output terminal, Q, connected to a pulser 52, such as a one-shot which has complement output terminals connected to respective fixed contacts 54, 56 of a single pole, double-throw switch which had its movable contact 58 connected to an A-C switch 60. The A-C switch 60 is connected in series with a solenoid or other actuator, indicated at 62.

In the condition of the system illustrated in PK]. 2, the magnetic card 20 has not been inserted in the housing. In such condition, the voltage level applied to the S terminal of the logic circuit 34 causes its output to be high, i.e., a logic 1. Also, the electronic switch 48 is open. When the card 20 is inserted in the housing to actuate the switch 22, thereby causing its movable contact 24 to move into engagement with the fixed contact 26, the voltage is removed from the S terminal of the logic circuit 34, and allows the logic circuit 34 to be conditioned by virtue of the voltage levels that appear at its input terminals D and C. In this regard, the pulser 32 is rendered operable to apply a pulse of short duration, e.g., a few microseconds, to terminal C. If the output of the gate network 50 is high at the end of the short pulse, the logic level at the Q output of the logic circuit 34 decreases, i.e., becomes false or O to trigger the pulser 52, which generates a pulse of sufficient duration, e.g., seconds, to permit the solenoid of the access apparatus to be operated. The gate network 50 in the above example operates to develop a high (logic l) output when all of its inputs are high, and develops a low or false (logic O") output when any of its inputs is low.

Referring to FIG. 4 along with FIG. 2, the graph shows respective curves 70, 72 which illustrate the decay of voltage across a pulsed coil whose field aids that of a card spot (curve 70) and a decay of voltage across such a coil whose field opposes the field of a card spot (curve 72.) It will be seen that at a time, t, corresponding to the duration of the pulse from the pulser 32, the voltage across a coil whose field aids that of the card spot will have decreased to zero, while that ofa voltage whose field is opposing that of its card spot is still relatively high. Accordingly, if at the time, t, the voltages across all of the pulsed coils 44 establish fields which oppose the fields of the card spots aligned therewith, all of the inputs to the gate network 50 are high, whereupon the pulser 52 is triggered to effect operation of the solenoid through the A-C switch 60. On the other hand, if the field of any pulsed coil aids that of the card spot aligned therewith, the associated input to the gate 50 will be low at time, t, whereupon the output of the gate is false and will prevent operation of the pulser 52.

An illustration and description of operation of the gating and logic circuitry of a flip-flop suitable for the logic circuit 34 is disclosed in the publication Motorola Digital integrated Circuits" (Motorola Semi- Conductor Products, lnc., July 1968 Similarly, the arrangements and operations of one-shot devices and flip-flops for the transient squelch circuit 30 and pulsers 32, 52, will be readily understood by those skilled in the art.

A built-in safety feature of the system of the invention as above-described is that it automatically ceases to perform the desired end function after a predetermined time, even if the card is a valid card and remains inserted in the housing. ln this connection, at the end of the time constant set into the pulser 52, the pulse therefrom terminates and the A-C switch 60 is opened to break the circuit to the solenoid. Thus, if the person inserting a valid card in the housing does not operate the door, gate, turnstile or the like of the access apparatus within the 5 seconds, he must first remove the card and then reinsert it.

The system of the invention is also provided with means to adapt to the situation wherein power is constantly applied to electromagnetic means for keeping access apparatus locked, and wherein power is interrupted to unlock the access apparatus upon inserting a card in the housing. For such apparatus, the movable contact 58 that is connected to the A-C switch 60 is moved to the fixed contact 56. By this connection, the A-C switch 60 remains operative, and the solenoid remains energized, until a valid card is inserted in the housing. As will be noted, this connection of the switch contact 58 causes a high output from the associated output terminal of the pulser 52 to be high, thus causing the A-C switch 60 to be closed until such output becomes low, or false. This occurs when a valid card is inserted in a housing, because the system functions in the manner above descirbed to cause the complement output terminals of the pulser 52 connected to the fixed contacts 54, 56 to be respectively high and low.

The system of this invention also includes means for effecting operation of the access apparatus by differently coded cards at different times, and also for permitting overlap operations at still other times when both cards can be used to operate the access apparatus. Referring to P10. 2, a switch is shown having a movable contact 82 selectively movable to one of three fixed contacts 84, 86, 88. In the arrangement illustrated, one contact 84 is shown with the legend day" another is shown with the legend nite and the other is shown as a neutral position for the movable contact. The movable contact 82 is shown connected to the gate network 50, and the two legend contacts 84, 88 are shown connected to respective resistor-coil junctions.

Viewed from left to right in FlG. 2, the fixed contacts 84, 88 are connected to the first and sixth resistor-coil junctions. When it is desired to use the time zone fea ture, the originally described connections from such junctions to the input of the gate network 50 are disconnected. In this regard, such originally described connections are shown including respective switches 90, 92 which are shown normally closed. Then the time zone feature is put into operation, such switches 90, 92 are opened. Alternatively, such switches could be dispensed with, and the originally described connections to the gate input could be broken by simply disconnecting the wires.

It will be noted that a fixed Contact 86 is a neutral position for the movable contact 82 signifying that the input connection to the gate 50 from the movable contact 82 is an open circuit. Assuming the switches 90, 92 are opened, this means that the gate inputs to the originally described connections of the associated resistor-coil junctions are also open circuits. The gate network 5th is adapted in conventional fashion to refleet high inputs to such open circuit conditions. Accordingly, if all of the remaining inputs to the gate network are high, signifying that all coil fields and spot fields are in opposing relation, the system will function as above descirbed to effect operation of the access apparatus.

When the movable contact 82 is switched to the fixed contact 84, any card inserted in the housing must have a spot aligned with and in opposing relation to the field of the first coil 44. Similarly, when the movable contact 82 is switched to the fixed contact 88, a card inserted into the housing must have a spot aligned with and in opposing relation to the field of the sixth coil. Thus, cards issued to day" card holders for operating access apparatus, e.g., parking lot gates, may have spots aligned with all coils except the sixth, while cards issued to nite" holders may have spots aligned with all but the first coil. But in such case, the system may be conditioned to operate the apparatus from either card by opening the switches 90, 92 and switching the movable contact 82 to the neutral fixed contact 86.

Still further, this invention provides means for selectively changing the magnetic characteristics of selected spots in the card 20, after it is inserted in the housing, and before it is removed. By way of example, the card 20, when inserted, may be properly coded to effect operation of anentrance gate to a parking lot. However, operation of an exit gate requires a differently coded card. Assume, for example, that for the card to operate the exit gate requires that one of its magnetized spots be demagnetized, i.e., neutralized, and that a previously uncoded portion be magnetized. Thus, in FIG. 1 there are shown two electromagnets 100, 102 located in openings in the lower wall 18 of the housing so that their upper ends are immediately adjacent the lower surface of the card 20. The electromagnet 100 is aligned with a previously magnetized spot, whereas the electromagnet 102 is aligned with an unmagnetized portion of the card. The coils of the electromagnets 100, 102 are wound so that when they are energized, the electromagnet 100 causes the previously magnetized spot to be demagnetized, and the electromagnet 102 causes the previously unmagnetized portion to be magnetized.

In FIG. 2, a switch 104 is shown having a movable contact 106 connected to an input of the gate network 50, such movable contact being selectively movable to engage one of the three fixed contacts 108, 110, 112. Two of the fixed contacts 108, 112, are connected to respective resistor-coil junctionsv As in the case of the previously described day nite provision, the originally described connections from such resistor-coil junctions are provided with switches 114, 116 to be opened when the movable contact 106 is switched to the fixed contact associated with the particular resistorcoil arrangement.

Referring to FIG. 3 along with FIG. 2, a voltage doubler 120 has inputs 122, 124 connected across the A-C switch 60. One input 122 is connected directly to one terminal of the A4: voltage source 38, and the other input 124 is connected to the other terminal of the AC voltage source 38 through a series circuit including a diode 126 resister 128, and a relay coil 130. The solenoid 132 for operating the access apparatus is connected between the input 124 and the terminal of the A-C voltage source to which the relay coil 130 is connected.

In the arrangement thus far described in FIG. 3, the coil of the solenoid 132 effectively permits the inputs 122, 124 of the voltage doubler 120 to be connected across the terminals of the A-C source 38. The voltage e doubler includes a conventional charging capacitor, which is charged to twice the peak value of the A-C voltage source. Thus, for a voltage source of approximately 12.6 volts, the peak value of which is approximately l9 volts, the charge on the capacitor in the voltage doubler is built up to 38 volts.

The voltage doubler 120 has one output connection 136 to one side of a rectifier 138, which may include a conventional SCR device. The other side of such rectifier includes normally open contents 140 which are adapted to be closed upon energization of the relay coil 130. The electromagnets 100, 102 have their coils connected between such other side of the rectifier 138 and the remaining output connection 142 of the voltage doubler 120.

in the illustrated arrangement, the coils of the electromagnets 100, 102 are connected in parallel between the doubler output 142 and the rectifier 138. When the relay coil is energized, and the switch contacts thereof are closed, the charge built up in the voltage doubler 120 is passed through the coils of the electromagnets 100, 102 to energize them. In the previously assumed example, the electromagnet 102 thus causes the previously unmagnetized spot to be magnetized and the electromagnet 100 causes the previously magne tized spot to be demagnetized. For the latter, a resistor 146 is shown connected in series with a coil of the electromagnet 100, the purpose of such resistor being to limit the current through the electromagnet so that the previously magnetized spot is not reverse polarized. 1f reverse polarization is required, however, the resistor 146 is eliminated.

Further regarding the spot changing scheme, it will be recognized that the system illustrated in FIG. 2 is located at both entrance and exit. Since a card 20 is effectively recorded at the entrance after effecting operation of the entrance gate, it can no longer be used to that end unless it is recoded again at the exit. Thus, when a card is changed at the entrance to permit it to be used to operate access apparatus at the exit, the system at the exit is conditioned to change the spot pattern back to what it was originally, so that the holder can later enter the parking lot when he inserts his card in the apparatus at the entrance.

We claim:

1. The combination, with access apparatus to be conditioned for operation from a spot magnetized card, of:

a plurality of electromagnet sensors each having a coil wound on a core;

a respective resistor connected in series with each coil;

a switch;

means to releasably support spot-mangetized card means in stationary position wherein the fields of spots therein are coaxial with respective coils, said switch being actuated by a portion of said card means when placed in said stationary position;

a voltage source;

means in circuit with said switch and operable when said switch is actuated by said card means to momentarily couple said voltage source simultaneously across said series-connected coils and resistors thereby to energize said coils;

a gate network;

respective connections to said gate network from the junctions of said series-connected coils and resistors,

said gate network developing a predetermined logic level output only when the coaxial magnetic fields of all the spots and energized coils are in the same relation; pulse developing means coupled to said switch, mo-

mentary coupling means and gate network, said pulse developing means being responsive to said predetermined logic level output to develop a pulse of predetermined duration greater than the momentary coupling of said voltage source to said coils and resistors; control means for the apparatus;

and enabling means responsive to and operable during the existance of said pulse to condition said control means for operating the apparatus, and for preventing operation of said control means upon expiration of said pulse.

2. The combination of claim 1, wherein said card means includes respective cards at the opposite ends of said sensors,

the fields of the spots in one card being coaxial with respective coils,

and the fields of the spots in the other card being coaxial with other respective coils.

3. The combination of claim 2, wherein said resistors are connected to said voltage source, and wherein said means for momentarily coupling said series-connected coils and resistors across said voltage source includes:

means operable upon actuation of said switch to develop a second pulse;

and an electronic switch connected between said coils and a point of reference potential; said switch being responsive to said second pulse to connect said coils to said point of reference potential.

4. The combination of claim 1, including a second switch,

said second switch having a movable contact and a pair of fixed contacts, said fixed contacts being connected to respective resistor-coil junctions and said movable contact being connected to said gate network, whereby the connection from either of such junctions to said gate network is via the movable contact when it engages the associated fixed contact.

5. The combination of claim 4, including a pair of electromagnets, each positioned adjacent respective portions of said card means;

and means operable upon said movable contact engaging one of said fixed contacts to energize said electromagnets,

said electromagnets when energized establishing magnetic fields of sufficient strength and directions to establish predetermined magnetic characteristics of the adjacent portions of said card means.

6. The combination of claim 5, wherein one of said respective portions of said card means is unmagnetized before, and is magnetized in a predetermined direction when, the electromagnet adjacent thereto is energized. l l= l l 

1. The combination, with access apparatus to be conditioned for operation from a spot magnetized card, of: a plurality of electromagnet sensors each having a coil wound on a core; a respective resistor connected in series with each coil; a switch; means to releasably support spot-mangetized card means in stationary position wherein the fields of spots therein are coaxial with respective coils, said switch being actuated by a portion of said card means when placed in said stationary position; a voltage source; means in circuit with said switch and operable when said switch is actuated by said card means to momentarily couple said voltage source simultaneously across said series-connected coils and resistors thereby to energize said coils; a gate network; respective connections to said gate network from the junctions of said series-connected coils and resistors, said gate network developing a predetermined logic level output only when the coaxial magnetic fields of all the spots and energized coils are in the same relation; pulse developing means coupled to said switch, momentary coupling means and gate network, said pulse developing means being responsive to said predetermined logic level output to develop a pulse of predetermined duration greater than the momentary coupling of said voltage source to said coils and resistors; control means for the apparatus; and enabling means responsive to and operable during the existance of said pulse to condition said control means for operating the apparatus, and for preventing operation of said control means upon expiration of said pulse.
 2. The combination of claim 1, wherein said card means includes respective cards at the opposite ends of said sensors, the fields of the spots in one card being coaxial with respective coils, and the fields of the spots in the other card being coaxial with other respective coils.
 3. The combination of claim 2, wherein said resistors are connected to said voltage source, and wherein said means for momentarily coupling said series-connected coils and resistors across said voltage source includes: means operable upon actuation of said switch to develop a second pulse; and an electronic switch connected between said coils and a point of reference potential; said switch being responsive to said second pulse to connect said coils to said point of reference potential.
 4. The combination of claim 1, including a second switch, said second switch having a movable contact and a pair of fixed contacts, said fixed contacts being connected to respective resistor-coil junctions and said movable contact being connected to said gate network, whereby the connection from either of such junctions to said gate network is via the movable contact when it engages thE associated fixed contact.
 5. The combination of claim 4, including a pair of electromagnets, each positioned adjacent respective portions of said card means; and means operable upon said movable contact engaging one of said fixed contacts to energize said electromagnets, said electromagnets when energized establishing magnetic fields of sufficient strength and directions to establish predetermined magnetic characteristics of the adjacent portions of said card means.
 6. The combination of claim 5, wherein one of said respective portions of said card means is unmagnetized before, and is magnetized in a predetermined direction when, the electromagnet adjacent thereto is energized. 